All electronic equipment requires a dc power supply. Power supplies for industrial and factory-automation equipment are a special case, though. Not only must they operate in what is considered a hazardous environment, but they must also be small, efficient, reliable, and economical. They’re a tough combination of design goals to achieve.
If you’re designing equipment for the Industrial Internet of Things (IIoT) or the Industry 4.0 movement, you must meet those challenging goals. For that reason, you should carefully consider a make vs. buy decision on the power supply. Why make your own if the budget allows you to acquire power supplies made especially for these applications?
IIoT and Industry 4.0
Just to be sure we’re all thinking the same way here, let’s define what we mean by IIoT and Industry 4.0. IIoT is a collection of technologies that apply to manufacturing and industrial processes. IIoT methods are designed to improve productivity and the ability to manage a major industrial investment.
IIoT uses sensors to monitor physical machines and manufacturing processes that determine the status of the system. The sensor data is communicated via a wireless or wired network to one or more computer systems, where it’s stored, analyzed, and then used to make smarter business decisions faster. Alternately, the sensor data can be used to immediately provide real-time control of selected machines or systems.
IIoT is generally considered to be part of an overall movement called Industry 4.0. The idea originated in Germany as “Industrie 4.0” and refers to our current fourth industrial revolution. The objective is to make factories and the smart grid intelligent by applying increased automation, improved communications, better monitoring and control, as well as advanced data-analysis techniques such as machine learning.
That said, think of all the wireless and wired sensors, data-collection gateways, control panels to monitor PLCs and robots, embedded controllers, and dedicated computer equipment that need power supplies.
IIoT Power Sources
Plenty of power-supply vendors are out there. But if you’re shopping for a supply targeting IIoT and related products, take a look at Austrian-based RECOM. Distributed by Digi-Key, the RECOM product line includes both ac-dc and dc-dc supplies to fit almost any IIoT application.
Some of their basic features are:
- Compact design: small size, low profile.
- Designed for PCB mounting.
- Low standby-current consumption.
- Wide input voltage range (85 ac-528 V ac; 120-370 dc)
- Wide operating temperature range (−40 to +85°C)
- Common dc output voltages (3.3, 5, 12, 15, 24, 48 V).
- Overvoltage, overload, and short-circuit protection.
- Required U.S., European, and international safety certifications.
- EMC-compliant; internal class B EMC filter included.
- Low cost with three-year warranty.
The RECOM RAC series offers a wide range of options. Here are some highlights.
Many small ac-dc supplies power the sensor networks. The RAC20-K series (Fig. 1) have compact design with a size range between 1 × 1 and 1 × 2 in. There are models available to deliver 1, 2, 3, 4 and 20 W. All of the usual output voltages are available, including ±12- and ±15-V versions. The RAC supplies have low standby power requirements (no load, 40 mW), yet can deliver up to 150% peak load. No external components are required.
1. The RAC20-K series of ac-dc power supplies (shown along with the RAC15-K) are often used in sensor networks.
RECOM’s RAC3.5/5-K/277 series consists of cost-effective 3.5- and 5-W ac-dc converters for IoT and industrial applications. They offer the common dc output voltages and an ac input range to 277 V ac. Temperature range is up to 90°C at 6 W. RECOM also makes the RAC03-SER/277, a series of ac-dc converters housed in a unique flat round package that’s designed to fit inside standard wall boxes. As a result, they’re well-suited for some building automation and security applications.
The RAC05-K/480 series of 5-W ac-dc modules (Fig. 2) designed for harsh industrial and outdoor mains uses, such as smart-grid, renewable-energy, smart-metering, and IoT applications. These PCB-mount converters are overvoltage- and overcurrent-protected without any external components needed. The modules support an operating temperature range from −40 to +80°C and come with fully protected outputs for EMC class A and B compliance. Input voltages range from 85 to 528 V ac with 5 V at 1 A or 12 V at 420 mA out.
2. RECOM’s RAC05-K/480 5-W ac-dc modules are equipped for harsh industrial and outdoor mains uses.
A Special Product
Many wireless sensors are battery-operated. While many if not most sensors in a factory can tap into available ac power, some battery-operated sensors are used in remote or inaccessible locations. One product that addresses this need is the R-78S, a dc-dc boost switching converter/regulator that uses a single 1.5-V AA cell for the input and delivers a stable 1.8-, 3.3-, or 3.6-V output (Fig. 3). The output is maintained with an input down to 0.65 V—the dropout voltage of a depleted AA cell. Its target applications are Bluetooth, Wi-Fi, and LoRa wireless modules, energy harvesting, and other battery-operated IoT products.
3. Targeting remote battery-operated sensors, the R-78S is a dc-dc boost switching converter/regulator that uses a single 1.5-V AA cell for the input.
RECOM offers a R-78S evaluation board that demonstrates the 93% efficiency performance of the RECOM R-78S switching regulator in conjunction with a single-cell AA battery.